background: surface microhardness is a physical property which access the effect of chemical and physical agents on hard tissues of teeth, and a useful way to examine the resistance of fluoride treated enamel against caries. the purpose of this study was to evaluate microhardness of enamel following ph-cycling through demineralization and remineralization using suspensions of dentifrices with d...

The exchange of chlorinated organic pollutants between air and vegetation in cold, mountain environments was investigated through the extraction of coniferous vegetation and high-volume air samples collected from the Canadian Rocky Mountains during the summers of 1999 and 2000. Concentrations of several compounds in vegetation increased as temperatures decreased, whereas atmospheric concentrati...

Evaluating conflicting theories about the influence of mountains on carbon dioxide cycling and climate requires understanding weathering fluxes from tectonically uplifting landscapes. The lack of soil production and weathering rate measurements in Earth's most rapidly uplifting mountains has made it difficult to determine whether weathering rates increase or decline in response to rapid erosion...

The ability to query enzyme molecules individually is transforming our view of catalytic mechanisms. Quiescin sulfhydryl oxidase (QSOX) is a multidomain catalyst of disulfide-bond formation that relays electrons from substrate cysteines through two redox-active sites to molecular oxygen. The chemical steps in electron transfer have been delineated, but the conformational changes accompanying th...

Thin coatings on metallic substrates are extensively used in mechanical, aerospace, microelectronic, optical, and medical applications. Coatings affect the surface properties of the system, while bulk properties and strength primarily depend on the substrate. In coated components subjected to thermal cycling, differences in physical properties and chemical nature between constituent parts of co...

This study was designed to examine the biomechanical and physiological responses between cycling on the Axiom stationary ergometer (Axiom, Elite, Fontaniva, Italy) vs. field conditions for both uphill and level ground cycling. Nine cyclists performed cycling bouts in the laboratory on an Axiom stationary ergometer and on their personal road bikes in actual road cycling conditions in the field w...

The purpose oi' the study was to investigate, through laboratory tests, the potential for developing fatigue indicators for which some merit was evident from prior research. The response of photographic emulsions, phosphor coatings,and chemical indicator coatings to physical and surface-chemical reactions associated with fatigue damage in 2024-T3 aluminum was investigated. Many indicators were ...

The functional significance and regulation of reversible S-acylation on diverse proteins remain unclear because of limited methods for efficient quantitative analysis of palmitate turnover. Here, we describe a tandem labeling and detection method to simultaneously monitor dynamic S-palmitoylation and protein turnover. By combining S-acylation and cotranslational fatty acid chemical reporters wi...